Copper radioisotopes can be used for imaging as well as for therapy and, thus, can form ideal theranostic pairs. The Cu(II) complexes of cross-bridged cyclam (cb-cyclam) derivatives are considered to be highly stable in vivo. However, the complexes are mostly formed under harsh conditions not compatible with sensitive biomolecules. Here, a new class of cb-cyclam derivatives, cross-bridged bis(phosphinate)cyclams ("cb-BPC"), were investigated. Ligands with one or two methylene-bis(phosphinate) -CH2-PO2H-CH2-PO2H(R) (R = H, OH, substituted alkyl) pendant arms were synthesized. Bifunctionalization on the distant phosphorus atom was carried out by employing P-nitrobenzyl (R = CH2-Ph-4-NO2) precursors and/or, for cb-BPC with two bis(phosphinate) pendant arms, by reactions of silyl-phosphites obtained by silylation of their P(O)-H fragments. The reactive bifunctional groups include amine, carboxylate, azide, isothiocyanate, maleimide and/or tetrazine, and also their orthogonally reactive combination in a single molecule of chelator. The cb-BPCs with one bis(phosphinate) arm were not efficiently radiolabelled with 64Cu. The cb-BPCs with two pendant arms were radiolabelled even at room temperature and with only a small excess of chelator, leading to a high specific activity. Radiolabelling was fully comparable with that of analogous bis(phosphinate) derivatives of cyclam and identical radiolabelling of cyclam and cb-cyclam derivatives was observed for the first time. The cb-BPCs with two bis(phosphinate) pendant arms represent a new class of rigid chelators for copper radioisotopes that are easily synthetically modifiable, highly hydrophilic and radiolabelled under mild conditions.
- Publication type
- Journal Article MeSH
The cellular adhesion receptor αvβ6-integrin is highly expressed in many cancers, e.g., pancreatic, lung, head-and-neck, cervical, bladder, and esophageal carcinoma. Multimerization of αvβ6-integrin-specific RGD peptides increases the target affinity and retention but affects biodistribution and pharmacokinetics. Amide formation of the terminal carboxylic acid moieties of the square-symmetrical bifunctional chelator DOTPI with 3-azidopropylamine yields derivatives with 4, 3, and 2 terminal azides and zero, 1, and 2 remaining carboxylic acids, respectively, whereby formation of the 2-cis-isomer is preferred according to NMR investigation of the Eu(III)-complexes. Cu(II)-catalyzed alkyne-azide cycloaddition (CuAAC) of the alkyne-functionalized αvβ6-integrin binding peptide cyclo[YRGDLAYp(NMe)K(pent-4-ynoic amide)] (Tyr2) yields the respective di-, tri-, and tetrameric conjugates for Lu-177-labeling. In mice bearing αvβ6-integrin-expressing xenografts of H2009 (human lung adenocarcinoma) cells, the Lu-177-labeled trimer's tumor-to-blood ratio of 112 exceeds that of the tetramer (10.4) and the dimer (54). Co-infusion of gelofusine (succinylated gelatin) reduces the renal uptake of the trimer by 89%, resulting in a 10-fold better tumor-to-kidney ratio, while no improvement of that ratio is observed with arginine/lysine, para-aminohippuric acid (PAH), and hydroxyethyl starch (HES) coinfusions. Since the Lu-177-labeled Tyr2-trimer outperforms the dimer and the tetramer, such trimers are considered the best lead structures for the ongoing development of αvβ6-integrin targeted anticancer theranostics.
- MeSH
- Antigens, Neoplasm * metabolism MeSH
- Chelating Agents * chemistry MeSH
- Click Chemistry MeSH
- Integrins * metabolism MeSH
- Humans MeSH
- Lutetium * chemistry MeSH
- Mice, Nude MeSH
- Mice MeSH
- Cell Line, Tumor MeSH
- Neoplasms drug therapy MeSH
- Oligopeptides * chemistry pharmacokinetics MeSH
- Radiopharmaceuticals pharmacokinetics chemistry therapeutic use MeSH
- Radioisotopes * chemistry MeSH
- Theranostic Nanomedicine methods MeSH
- Tissue Distribution MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Two copper(II) complexes containing diplacone (H4dipl), a naturally occurring C-geranylated flavanone derivative, in combination with bathophenanthroline (bphen) or 1,10-phenanthroline (phen) with the composition [Cu3(bphen)3(Hdipl)2]⋅2H2O (1) and {[Cu(phen)(H2dipl)2]⋅1.25H2O}n (2) were prepared and characterized. As compared to diplacone, the complexes enhanced in vitro cytotoxicity against A2780 and A2780R human ovarian cancer cells (IC50 ≈ 0.4-1.2 μM), human lung carcinoma (A549, with IC50 ≈ 2 μM) and osteosarcoma (HOS, with IC50 ≈ 3 μM). Cellular effects of the complexes in A2780 cells were studied using flow cytometry, covering studies concerning cell-cycle arrest, induction of cell death and autophagy and induction of intracellular ROS/superoxide production. These results uncovered a possible mechanism of action characterized by the G2/M cell cycle arrest. The studies on human endothelial cells revealed that complexes 1 and 2, as well as their parental compound diplacone, do possess anti-inflammatory activity in terms of NF-κB inhibition. As for the effects on PPARα and/or PPARγ, complex 2 reduced the expression of leukocyte adhesion molecules VCAM-1 and E-selectin suggesting its dual anti-inflammatory capacity. A wide variety of Cu-containing coordination species and free diplacone ligand were proved by mass spectrometry studies in water-containing media, which might be responsible for multimodal effect of the complexes.
- MeSH
- Anti-Inflammatory Agents pharmacology chemistry MeSH
- Autophagy drug effects MeSH
- Flavanones * pharmacology chemistry MeSH
- Coordination Complexes * pharmacology chemical synthesis chemistry MeSH
- Humans MeSH
- Copper * chemistry pharmacology MeSH
- Cell Line, Tumor MeSH
- Cell Proliferation * drug effects MeSH
- Antineoplastic Agents * pharmacology chemistry chemical synthesis MeSH
- Reactive Oxygen Species metabolism MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
A bis(chalcone) molecule (H2L) was synthesized via Aldol's condensation from terephthalaldehyde and 2'-hydroxyacetophenone and it was used as bridging ligand for the preparation of five dinuclear copper(II) complexes of the composition [Cu(NN)(μ-L)Cu(NN)](NO3)2⋅nH2O (n = 0-2) (1-5), where NN stands for a bidentate N-donor ligand such as phen (1,10-phenanthroline, 1), bpy (2,2'-bipyridine, 2), mebpy (5,5'-dimethyl-2,2'-dipyridine, 3), bphen (bathophenanthroline, 4) and nphen (5-nitro-1,10-phenanthroline, 5). The compounds were characterized by different suitable techniques to confirm their purity, composition, and structure. Moreover, the products were evaluated for their in vitro cytotoxicity on a panel of human cancer cell lines: ovarian (A2780), ovarian resistant to cisplatin (A2780R), prostate (PC3), osteosarcoma (HOS), breast (MCF7) and lung (A549), and normal fibroblasts (MRC-5), showing significant cytotoxicity in most cases, with IC50 ≈ 0.35-7.8 μM. Additionally, the time-dependent cytotoxicity and cellular uptake of copper, together with flow cytometric studies concerning cell-cycle arrest, induction of cell death and autophagy and induction of intracellular ROS/superoxide production in A2780 cells, were also performed. The results of biological testing on A2780 cells pointed out a possible mechanism of action characterized by the G2/M cell cycle arrest and induction of apoptosis by triggering the intrinsic signalling pathway associated with the damage of mitochondrial structure and depletion of mitochondrial membrane potential. SYNOPSIS: Dinuclear Cu(II) complexes bearing a bridging bis(chalcone) ligand revealed high in vitro cytotoxicity, initiated A2780 cell arrest at G2/M phase and efficiently triggered intrinsic pathway of apoptosis.
- MeSH
- Apoptosis MeSH
- Chalcone * pharmacology MeSH
- Chalcones * pharmacology MeSH
- Coordination Complexes * pharmacology chemistry MeSH
- Humans MeSH
- Ligands MeSH
- Copper chemistry MeSH
- Cell Line, Tumor MeSH
- Ovarian Neoplasms * MeSH
- Antineoplastic Agents * pharmacology chemistry MeSH
- Check Tag
- Humans MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Two cationic [Cu2(L1-2)2](ClO4)2 (1, 2), and four neutral doubly bridged-phenoxido-copper(II) complexes [Cu2(L3-4)2] (3, 4) and [Cu2(L5-6)2(H2O)]‧2H2O (5, 6) as well as 1D polymeric catena-[Cu(L7)] (7), where HL1-2 and H2L3-7 represent tripodal tetradentate pyridyl or aliphatic-amino groups based 2,4-disubstituted phenolates, were synthesized and thoroughly characterized by various spectroscopic methods and single crystal X-ray analysis. The molecular structures of the complexes exhibited diverse geometrical environments around the central Cu(II) atoms. The in vitro antiproliferative activity of the isolated complexes and selected parent free ligands were screened against some human cancer cell lines (A2780, A2780R, PC-3, 22Rv1, MCF-7). The most promising cytotoxicity against cancer cells were obtained for 1-6, while complex 6 was found as the best performing as compared to the reference drug cisplatin. The cytotoxicity study of complex 6 was therefore extended to wider variety of cancer cell lines (HOS, A549, PANC-1, CaCo2, HeLa) and results revealed its significant cytotoxicity on all investigated human cancer cells. The cell uptake study showed that cytotoxicity of 6 (3 μM concentration and 24 h of incubation) against A2780 cells was almost independent from the intracellular levels of copper. The effect of complexes 4, 6 and 7 on cell cycle of A2780 cells indicates that the mechanism of action in these complexes is not only different from that of cisplatin but also different among them. Complex 7 was able to induce apoptosis in A2780 cells, while complexes 4 and 6 did not and on the other hand, they showed considerable effect on autophagy induction and there are some clues that these complexes were able to induce cuproptosis in A2780 cells.
- MeSH
- Caco-2 Cells MeSH
- Cisplatin MeSH
- Coordination Complexes * pharmacology chemistry MeSH
- Crystallography, X-Ray MeSH
- Humans MeSH
- Ligands MeSH
- Copper chemistry MeSH
- Molecular Structure MeSH
- Cell Line, Tumor MeSH
- Ovarian Neoplasms * MeSH
- Antineoplastic Agents * pharmacology chemistry MeSH
- Check Tag
- Humans MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
A novel fluorescent ligand (H2LCl⋅1.5CH3OH, 1) was synthesized and metal complexes of 1 with Mn(II), Fe(III), Ni(II), Cu(II), and Zn(II) were obtained as Mn(HL)2Cl2 (2), Fe(HL)2Cl3⋅3H2O (3), Ni(L)(HL)Cl⋅8H2O (4), Cu(HL)Cl2⋅4H2O (5), Zn(H2L)Cl3 (6), respectively. These compounds were identified by spectroscopic methods, elemental analysis, molar conductivity, and single-crystal X-ray crystallography. According to the crystal structure of 4 nickel (II), center is surrounded by two ligands in a distorted octahedral geometry. The ligand and its complexes are soluble in water and have excellent stability. In vitro anti-proliferative activity of these compounds was evaluated against human breast adenocarcinoma (MCF-7) and human lipo-sarcoma (SW-872) as cancer cells and human fibroblasts (HFF-2) as normal cells by MTT assay. Interestingly, complex 5 exhibited excellent activity against both cancer cells with low IC50 value 22.18 ± 0.35 μg/mL (35.66 ± 0.56 μM) for SW-872 and 79.41 ± 3.54 μg/mL (127.6 ± 5.69 μM) for MCF-7 among the compounds and in comparison with paclitaxel (PTX) which acts finely. Morphological changes were evaluated by flow cytometry that revealed apoptosis is the main cause of cell death. Likewise, cell cycle studies indicated the cell cycle arrest in the G1 and S phases for complex 5 against MCF-7 and SW-872 cancer cells, while complex 6 could arrest the MCF-7 and SW-872 cells in G2 and G1 phases, respectively. All of the compounds are fluorescent which enabled us to monitor the uptake and intracellular distribution in living human cancer cells by fluorescence microscopy.
- MeSH
- Coordination Complexes * pharmacology chemistry MeSH
- Humans MeSH
- Ligands MeSH
- Copper chemistry MeSH
- Antineoplastic Agents * pharmacology chemistry MeSH
- Schiff Bases pharmacology chemistry MeSH
- Thiosemicarbazones * chemistry MeSH
- Ferric Compounds MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The effects of two anticancer active copper(II) mixed-ligand complexes of the type [Cu(qui)(mphen)]Y·H2O, where Hqui = 2-phenyl-3-hydroxy- 1H-quinolin-4-one, mphen = bathophenanthroline, and Y = NO3 (complex 1) or BF4 (complex 2) on the activities of different isoenzymes of cytochrome P450 (CYP) have been evaluated. The screening revealed significant inhibitory effects of the complexes on CYP3A4/5 (IC50 values were 2.46 and 4.88 μM), CYP2C9 (IC50 values were 16.34 and 37.25 μM), and CYP2C19 (IC50 values were 61.21 and 77.07 μM). Further, the analysis of mechanisms of action uncovered a non-competitive type of inhibition for both the studied compounds. Consequent studies of pharmacokinetic properties proved good stability of both the complexes in phosphate buffer saline (>96% stability) and human plasma (>91% stability) after 2 h of incubation. Both compounds are moderately metabolised by human liver microsomes (<30% after 1 h of incubation), and over 90% of the complexes bind to plasma proteins. The obtained results showed the potential of complexes 1 and 2 to interact with major metabolic pathways of drugs and, as a consequence of this finding, their apparent incompatibility in combination therapy with most chemotherapeutic agents.
- Publication type
- Journal Article MeSH
A series of six heteroleptic copper(II) complexes with 2'-hydroxy-4-(dimethylamino)chalcone (HL) with the composition [Cu(N-N)(L)]NO3 (1-6), where N-N stands for dmbpy = 5,5'-dimethyl-2,2'-bipyridine (1), bphen = 4,7-diphenyl-1,10-phenanthroline (2), dbbpy = 4,4'-di-tert-butyl-2,2'-bipyridine (3), nphen = 5-nitro-1,10-phenanthroline (4), bpy = 2,2'-bipyridine, (5), and dpa = 2,2'-dipyridylamine (6), was prepared and thoroughly characterized. The in vitro cytotoxicity screening on eight human cancer cell lines identified complex 2, containing the bulkiest N-donor ligands (bphen) as highly cytotoxic against cancer cells, with IC50 values ranking from 1.0 to 2.3 μM, with good selectivity and low toxicity against healthy human fetal lung fibroblasts MRC-5. The cell-based assays, involving the most effective complex 2 in A2780 cancer cells, revealed its strong pro-apoptotic effects based on the effective activation of caspases 3/7, ROS overproduction, and autophagy in the A2780 cells while not impeding the cell cycle and mitochondrial membrane functions. The cellular uptake studies in A2780 and 22Rv1 cells uncovered no intracellular transport of the cationic complex 2, supporting the hypothesis that the in vitro anticancer effects of complex 2 are based on the combined extrinsic activation of apoptosis and autophagy induction.
- Publication type
- Journal Article MeSH
Amanita muscaria is an ectomycorrhizal mushroom that commonly grows at metal-polluted sites. Sporocarps from the lead smelter-polluted area near Příbram (Central Bohemia, Czech Republic) showed elevated concentrations of Cd and Zn. Size exclusion chromatography of the cell extracts of the sporocarps from both polluted and unpolluted sites indicated that substantial part of intracellular Cd and Zn was sequestered in 6-kDa complexes, presumably with metallothionein(s) (MT). When the cultured mycelial isolates were compared, those from Příbram were more Cd-tolerant and accumulated slightly less Cd and Zn than those from the unpolluted site. The analysis of the available A.muscaria sequence data returned a 67-amino acid (AA) MT encoded by the AmMT1 gene. Weak Cd and Zn responsiveness of AmMT1 in the mycelia suggested its metal homeostasis function in A.muscaria, rather than a major role in detoxification. The AmMT1 belongs to a ubiquitous peptide group in the Agaricomycetes consisting of 60-70-AA MTs containing seven cysteinyl domains and a conserved histidyl, features observed also in a newly predicted, atypical 45-AA RaMT1 of the Zn-accumulator Russula bresadolae in which the C-terminal cysteinyl domains VI and VII are missing. Heterologous expression in metal-sensitive yeast mutants indicated that AmMT1 and RaMT1 encode functional peptides that can protect cells against Cd, Zn, and Cu toxicity. The metal protection phenotype observed in yeasts with mutant variants of AmMT1 and RaMT1 further indicated that the conserved histidyl seems to play a structural, not metal binding role, and the cysteinyls of the C-terminal domains VI and VII are important for Cu binding. The data provide an important insight into the metal handling of site-associated ectomycorrhizal species disturbed by excess metals and the properties of MTs common in Agaricomycetes.
A series of new heteroleptic copper(II) complexes of the composition [Cu(L)(bpy)]NO3·2MeOH (1), [Cu(L)(dimebpy)]NO3·2H2O (2), [Cu(L)(phen)]NO3·2MeOH (3), [Cu(L)(bphen)]NO3·MeOH (4), [Cu(L)(dppz)]NO3·MeOH (5) was prepared, where HL = 3-(3,4-dihydroxyphenyl)-5-hydroxy-8,8-dimethyl-6-(3-methylbut-2-ene-1-yl)-4H,8H-benzo[1,2-b:3,4-b']dipyran-4-one, (pomiferin) and bpy = 2,2'-bipyridine, dimebpy = 4,4'-dimethyl-2,2'-bipyridine, phen = 1,10-phenanthroline, bphen = 4,7-diphenyl-1,10-phenanthroline, and dppz = dipyrido[3,2-a:2',3'-c]phenazine. The complexes were characterized using elemental analysis, infrared and UV/Vis spectroscopies, mass spectrometry, thermal analysis and conductivity measurements. The in vitro cytotoxicity, screened against eight human cancer cell lines (breast adenocarcinoma (MCF-7), osteosarcoma (HOS), lung adenocarcinoma (A549), prostate adenocarcinoma (PC-3), ovarian carcinoma (A2780), cisplatin-resistant ovarian carcinoma (A2780R), colorectal adenocarcinoma (Caco-2) and monocytic leukemia (THP-1), revealed the complexes as effective antiproliferative agents, with the IC50 values of 2.2-13.0 μM for the best performing complexes 3 and 5. All the complexes 1-5 showed the best activity against the A2780R cells (IC50 = 2.2-6.6 μM), and moreover, the complexes demonstrated relatively low toxicity on healthy human hepatocytes, with IC50 > 100 μM. The complexes were evaluated by the Annexin V/propidium iodide apoptosis assay, induction of cell cycle modifications in A2780 cells, production of reactive oxygen species (ROS), perturbation of mitochondrial membrane potential, inhibition of apoptosis and inflammation-related signaling pathways (NF-κB/AP-1 activity, NF-κB translocation, TNF-α secretion), and tested for nuclease mimicking activity. The obtained results revealed the corresponding complexes to be effective antiproliferative and anti-inflammatory agents.
- MeSH
- Anti-Inflammatory Agents pharmacology MeSH
- Apoptosis drug effects MeSH
- Benzopyrans chemistry pharmacology MeSH
- Flavonoids metabolism pharmacology MeSH
- Isoflavones chemistry pharmacology MeSH
- Coordination Complexes chemistry pharmacology MeSH
- Humans MeSH
- Copper chemistry metabolism pharmacology MeSH
- Cell Line, Tumor MeSH
- Cell Proliferation drug effects MeSH
- Antineoplastic Agents pharmacology MeSH
- Reactive Oxygen Species metabolism MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
